A number of remote access tools and minimally invasive surgical tools which incorporate handles with unlimited (“infinite”) rotation mechanisms are known, for example, WO 2007/146894 A2. This application describes, for example, laparoscopy tools primarily consisting of a proximal handle, a tool frame/tool shaft and distal end-effector (EE). In some of these laparoscopic devices, to rotate the end-effector about the tool shaft axis (i.e., to provide a roll rotation of the end-effector), the user may have to rotate the handle about its own center axis. While the handle may fit or conform in the user's hand, palm, and/or fingers in the nominal condition (i.e., prior to any roll rotation), it may no longer continue to fit/conform with the user's hand during and after the roll rotation. In fact, the handle may start to collide with areas of the hand holding the device during rotation, typically limiting the amount of roll rotation and/or requiring repositioning of the handle within the surgeon's hand to achieve maximum roll rotation at the end-effector. Thus, many of these devices may require more than one hand to operate, or may require repositioning of the device during operation within a user's hand in order to continue to roll in a single direction beyond a limited amount of roll. The process of repositioning usually results in a loss of access to the input joint/mechanism between the tool shaft/frame and handle and loss of ergonomics at the handle to hand interface. Attempts have been made to address the challenge of limited rotation and reduced ergonomics by providing a rotational joint in the handle between the stationary portion of the handle that is held by user's hand, palm, finger(s) and/or thumb in the nominal condition and the roll portion that is rotated with respect to the stationary portion about its center axis by the user's finger(s) and/or thumb; these attempts have met with only limited success, in part because rolling the device in this manner may result in winding of internal cabling, including actuating cables and the like when rolling the stationary portion relative to the roll portion (e.g., dial, handle dial, rotation dial or the like). The stationary portion of the handle is defined stationary as far as roll rotation motion is concerned. This stationary portion may move along with the user's hand to provide other degree of freedoms (e.g., pitch and yaw rotations in articulating laparoscopic devices).
These devices that incorporate the stationary portion and roll portion in the handle assembly, may be articulating or non-articulating. In some non-articulating devices, the handle and tool shaft can be rigidly connected and rotation of the entire handle may drive rotation of the tool shaft and end-effector. In other non-articulating devices, the handle and tool shaft can be rigidly connected and the handle may be equipped with a dial, where the dial is connected to the end effector and drives the rotation of the end-effector via a roll transmission member routed through the tool shaft. Furthermore, laparoscopic devices are becoming more complex and catering to challenging laparoscopic procedures. Laparoscopic tools may now include articulating end-effectors that can be driven by an input joint between the tool shaft and the handle. Articulating end-effectors enable the surgeon to alter the axis of roll rotation at the end-effector by articulating the handle about an input joint with respect to the tool shaft. The handle in such device is not rigidly connected to the tool shaft but instead connected via an input joint that generally allows two articulation degrees of freedoms, e.g., yaw rotation and pitch rotation, and constrains (and therefore transmits) roll rotation. In some articulating devices, rotation of the end effector may be transmitted via rotation of the dial portion of the handle, which further transmits roll to the end effector via rotation of tool shaft. Here, tool shaft is connected to the handle via an input articulation joint providing yaw and pitch degree of freedoms but transmits roll rotation from the handle to the tool shaft. Similarly, the roll rotation of the tool shaft is transmitted to the end-effector via the output articulating joint. An example of such device configuration is an articulation device sold by Novare™ (International Patent Application Publication WO2007/146894 A2). In other articulating devices, articulation transmission and roll transmission are decoupled such that roll is directly transmitted from the rotation of the dial portion of handle to the end-effector via a separate roll transmission member and not via the kinematics of the input articulation joint, tool shaft, and output articulation joint. This roll transmission member may be torsionally stiff to transmit roll rotation. This roll transmission member may or may not be routed through the input articulation joint and/or the tool frame/tool shaft. An example of such device configuration is an articulation device sold by Covedien™ (U.S. Pat. No. 8,603,135). Some articulating devices in aforementioned configuration provide unlimited roll capability of the articulated end effector, caused by rotation of the handle dial about its own center axis.
Typically, the enhanced dexterity that these articulating tools may offer comes with the tradeoff of increased resistance to roll rotation of the handle and therefore the end-effector when the end-effector and therefore the handle are articulated. This resistance may get further exemplified when the handle input lever to operate the end effector actuation (e.g., opening and closing of a moving portion of the end effector relative to a reference portion of the end effector, that does not move relative to the moving portion) is engaged while performing articulation as well as roll rotation of the end effector. Engagement of a handle input lever to actuate opening/closing of an end-effector having a jaw at the end of the tool shaft, typically results in high loads generated between the stationary portion of the handle held by the user and rotation portion of the handle (dial), that interface with each other to allow rotation. The result of the high load between these independent bodies is typically an increase in frictional resistance to roll rotation which limits the surgeon's ability to use finesse rotation input at the handle to control the end-effector roll rotation. The high jaw open/close actuation loads are typically transmitted from the handle input by a transmission member such as a steel cable, steel wire, etc. or a monofilament steel or Nitinol rod, etc. These types of transmission members function well to transfer loads to a remote aspect of an instrument, but, due to the complexity in providing articulation, roll and actuation functionality to the end effector in such devices, as well as working within a tight volume to incorporate features to meet these functionalities, it is challenging to incorporate joints and bodies that meet the structural requirements to be able to provide aforementioned functionalities. One of the challenges may be the transmission of roll from handle to the end effector and at the same time, transmit end effector actuation from handle to the end effector.
Described herein are apparatuses (e.g., mechanisms, devices, tools, machines, systems, etc.) including handles with an unlimited roll mechanism which may address these problems.